FIG. 1 is the system diagram of System Architecture Evolution (SAE), thereby, User Equipment (UE) 101 is terminal equipment used to receive data. Evolved Universal Terrestrial Radio Access Network (E-UTRAN) 102 is a wireless access network, including macro base station (eNodeB/NodeB) that provides wireless access network interface for a UE. A Mobile Management Entity (MME) 103 is in charge of managing mobile context, session context and security information of UE. A Service Gateway (SGW) 104 mainly provides the functions for user plane. The MME 103 and SGW 104 can be in the same physical entity. A Packet data network Gateway (PGW) 105 is in charge of functions such as billing, lawful interception, and the like, and can be in the same physical entity as SGW 104. Policy Charging and Rules Function (PCRF) 106 provides policy for Quality of Service (QoS) and billing rules. Serving General Packet Radio Service (GPRS) Support Node (SGSN) 108 is the network node equipment providing routing for the data transmission in Universal Mobile Telecommunications System (UMTS). Home Subscriber Server (HSS) 109 is the home ownership subsystem of UE, which is in charge of protecting the user information including, current position of user equipment, the address of service node, user security information, packet data of user equipment, and so forth.
It is proposed in 3GPP that the network needs to be capable of supporting local Internet Protocol access (LIPA). LIPA means that UE access the home network or enterprise internal network through Home eNodeB (HeNB) or Home NodeB (HNB), when executing LIPA, select or reselect the user plane node near the HNB or select the user plane node located in HeNB/HNB access network for UE. Among them, a user plane node can be core network equipment or a gateway. For SAE system, a user plane node can be SGW or PGW or Local Gateway (LGW). For UMTS system, a user plane node can be SGSN or Gateway GPRS Support, Node (GGSN).
At present, LIPA does not support mobility in 3GPP Release-10 (referred to as R10 hereinafter). When the UE moves out of HeNB/HNB supporting LIPA, all services related to LIPA of this UE are terminated. In R10, this HeNB/HNB and LGW are designed in the same physical entity.
LIPA supports mobility in 3GPP Release-11 (referred to as R11 hereinafter). When the UE moves out of HeNB/HNB supporting LIPA, and only when the UE is still in the enterprise network or home network, it is required that LIPA service of the UE cannot be terminated. In R11, individual LGW and HeNB/HNB are defined, HeNB/HNB and LGW are not designed in the same physical entity, and an open interface between the two entities will be defined.
At present, the biggest difference between LIPA service in R11 and LIPA service in R10 is: LIPA service in R11 supports mobility while LIPA service in R10 does not support mobility; LIPA service in R11 supports multiple PDN connections and multiple bearer requests while LIPA service in R10 only supports single PDN connection and single bearer request.
With the introduction of new function and new node in R11, in a R11 network, it may happen that R10 equipment node and R11 equipment node coexist. FIG. 2a shows a kind of LTE network structure in which the core network node MME in R11 connects to both HeNB supporting LIPA function in R10 and HeNB supporting LIPA function in R11 at the same time. FIG. 2b shows a kind of UMTS network structure in which SGSN connects to HNB supporting LIPA function in R10 and HNB supporting LIPA function in R11 through HNB GW at the same time. For an enterprise network, it may also happen that R10 equipment and R11 equipment coexist. It results in the fact that subscription information of UE may be inconsistent with the capability of access equipment, so it is not guaranteed that LIPA service can be established correctly. For example, the UE signs up for R10 service, but is accessed to HeNB supporting LIPA in R11; or the UE signs up for R11 service, but is accessed to HeNB supporting LIPA in R10; under these situations, since network node does not know equipment capability of the HeNB that UE accesses, the network service connection process may lead to LIPA service failure or incorrect success (like establishing LIPA service in R11 for the user signing up for R10 service), and result in a bad service experience for the user. The user does not know the deployment of network usually, but only knows the service type signed up with the operator.
FIG. 3 provides the network structure of R11 LIPA. The interface between HeNB and LGW is SL interface, the protocol stack supported by this interface has two possibilities currently: possibility 1: SL interface supports both GTP-C and GTP-U protocol at the same time; possibility 2: SL interface supports GTP-U protocol. What is needed is a solution to these two possible structures respectively.